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排序方式: 共有483条查询结果,搜索用时 153 毫秒
71.
Eloi Feitosa Monique Lemos Renata D. Adati 《Journal of surfactants and detergents》2019,22(5):1083-1091
One of the most challenging characteristics not fully understood yet of the cationic surfactant salt dioctadecyldimethylammonium (DODA+) halide is concerned with the effects of the counterion (usually Br− and Cl−) on the surfactant assembly into vesicle structures in aqueous solution. These counterions play a key role in the self-organization of DODA+ into bilayer structures. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) techniques were used here to investigate systematically the effects of the single salts NaCl and NaBr, respectively, on the thermal behavior and structural organization of the cationic dioctadecyldimethylammonium bromide and chloride (DODAB and DODAC) in water. The results undoubtedly indicate that the added Br− or Cl−, respectively, into DODAC and DODAB aqueous dispersions, replaces partially the bound counterions (Cl− and Br−) from the vesicles, yielding formation of DODAB/DODAC mixed vesicles. As a conclusion, single salts may be used to tune the thermal and structural characteristics of cationic vesicles. 相似文献
72.
73.
To improve the use of ergonomics tools by construction workers, the effect of two guidance strategies – a face-to-face strategy (F2F) and an e-guidance strategy (EG) – of a participatory ergonomics intervention was studied. Twelve construction companies were randomly assigned to the F2F group or the EG group. The primary outcome measure, the percentage of workers using ergonomics tools, and secondary outcome measures – work ability, physical functioning and limitations due to physical problems – were assessed using surveys at baseline and after 6 months. Additionally, a cost-benefit analysis was performed on company level. No differences in primary and secondary outcomes were found with the exception of the use of ergonomics tools to adjust working height (F2F +1%; EG +10%; p?=?.001). Newly-implemented tools were used by 23% (F2F) and 42% (EG) of the workers (p?=?.271). Costs were mainly determined by guidance costs (F2F group) or purchase costs (EG group).
Practitioner Summary: Participatory strategies aim to stimulate behavioural change of stakeholders to increase the use of ergonomics tools. Two guidance strategies – face-to-face or e-mail interventions – among construction companies were studied. Both guidance strategies led to an increase in the use of new ergonomics tools. 相似文献
74.
Pauline Glatz Monique Comte Lionel Montagne Bertrand Doumert Fabrice Cousin Laurent Cormier 《Journal of the American Ceramic Society》2020,103(9):4969-4982
Li2O-Al2O3-SiO2 (LAS) glass-ceramics have important industrial applications and bulk nucleation is usually achieved by using nucleating agents. In particular, P2O5 is an efficient agent in glasses containing a low level of Al2O3 but its role in the first stages of nucleation is not well established. In this study, we combine structural investigations from local to mesoscales to describe the structural evolution during crystallization of LAS glass-ceramics. Local environment is probed using 29Si and 31P MAS-NMR, indicating organization of P in poorly crystallized Li3PO4 species prior to any crystallization. To better understand the detailed nanoscale changes of the glass structure, 31P-31P DQ-DRENAR homonuclear correlation experiments have been carried out, revealing the gradual segregation of P atoms associated with the formation of disordered Li3PO4. Small-angle neutron scattering data also show the apparition of nanoscale heterogeneities associated with Li3PO4 species upon heating treatments and allow the determination of their average sizes. These new structural information enhance our understanding of the role of P in nucleation mechanisms. Nucleation is initiated by gradual change in P environment implying P segregation upon heating treatments, forming disordered Li3PO4 heterogeneities. The segregation of P atoms enables the precipitation of meta- and disilicate phases. 相似文献
75.
The crystallization process of metallic glass Zr65Al7.5Ni10Cu17.5, (atom fraction in %) were studied by transmission electron microscopy and X-ray diffraction. Two stages of crystallization process, which are indicated by the two exothermic peaks in the differential scanning calorimetry diagram, were studied separately. It is found that the phases in the various stage of the crystallization are different, In the first stage, it consists mainly of tI-CuZr2 and tP-Al2Zr3 phases, between which a definite orientation relationship is found. While in the second stage, in addition to the above phases, phase hP2-Al2NiZr6 and phase hP3-α-Zr appear, between which another orientation relationship is also found. At the same time, a comparison is made based on the study of the phases exist in the arc-melted master ingot. The lattice parameters of the identified phases were determined and some interesting similarities were found. According to these similarities, all the phases were classified into two groups. The fi 相似文献
76.
Juliana dos Santos Rafaela S. de Oliveira Thayse V. de Oliveira Maiara C. Velho Martina V. Konrad Guilherme S. da Silva Monique Deon Ruy C. R. Beck 《Advanced functional materials》2021,31(16):2009691
3D printing and nanotechnology have been two important tools in the development of therapeutic approaches for personalized medicine. More recently, their alliance has been improved in an effort to build innovative, versatile, multifunctional, and/or smart medical and pharmaceutical products. Therefore, an extensive review about scientific studies that ally 3D printing and nanomaterials in the development of new approaches for pharmaceutical and medical applications for the treatment and prevention of diseases is presented here. The articles are classified into five categories according to their main application: Cell growth and tissue engineering, antimicrobial, drug delivery, stimulus-response, and theranostics. Semisolid extrusion, inorganic nanoparticles, and cell growth and tissue engineering are the most reported 3D printing technique, type of nanomaterial, and application, respectively. The increase in papers dedicated to these areas is also notable, especially in the 2019 and 2020, when semisolid extrusion became the most used technique, overcoming fused deposition modelling. In fact, this review highlights that the possibility of an alliance between 3D printing and nanotechnology for the production of multiscale materials is undoubtedly a great opportunity for knowledge and innovation in the pharmaceutical and medical area. 相似文献
77.
This paper aims at positioning organizational design as an important phenomenon in the field of project management with a high potential of contributing to organizational theory. While organizational design has been neglected by scholars of management and organizational theory, it has been of great interest to those from the project management field. This incongruence—comprising the focus of this study—calls for new insights on theorization in context. The paper provides a preliminary theoretical framework combining contingency theory, the historical approach and social theory to understand organizational design, both as a thing and as a process. It provides empirical evidence from three case studies in healthcare. Findings confirm the specificity of each design while at the same time adopting a similar temporal pattern. We take this opportunity to highlight the seminal work of Rodney Turner on project-based organization and design.
Executive summary
In this day and age, it is commonplace to assert that organizations are complex and that they change continuously over time. The complexity is said to exist, for example, in large organizations dealing with multiple competing projects while at the same time performing their regular operations. The concept of organizational design refers to both the resulting organization (the thing) and the process of performing the design. The field of project management has made many theoretical contributions to organizational design; yet it has also created confusion by introducing a plurality of terms for describing and understanding such organizations.Organizational design is increasingly a topic in the literature from management and organizational theory and, especially, from project management. A review of the literature from both fields demonstrates that contingency theory is still considered as a major theoretical foundation for situating the organization within its context. The review also points to an increasing interest in social perspectives taking into account politics, organizational dynamics, paradoxes and pluralism. In addition, it shows an opportunity for scholars in project management to contribute to management and organizational theory.This research proposes a pluralist theoretical framework for tackling contingency theory with the historical approach and social theory.The empirical setting is comprised of complex large organizations—in this case, three university hospitals engaged in major organizational transformations—that are challenged to pursue their regular operations while undertaking multiple completing projects. Interestingly, the three hospitals are from the same geographical region. The organizational design was thus a crucial question and, in light of the complexity, no one-size-fits-all type of solution was strived for.Results confirmed the prevalence of individual organizational design rather than mimetism, or homogenization, between the three hospitals. Being in the same region, the heads of the respective project management offices met on a number of occasions to exchange about their challenges and solutions. Nevertheless, in the end each hospital made an individual decision regarding its organizational design.The study also identified organizational design as an ongoing process, introducing the concept of trajectory to illustrate how projects and organizational design change over time. In doing so, we observed a pattern where reflection and sense-making took place before engaging in any specific decision regarding the organizational design.The theoretical contribution of this research is to demonstrate the potential of pluralist theoretical frameworks for understanding complex phenomena such as organizational design in the context of managing multiple projects. More specifically, the process view of organizational design was found to reveal new insights that would have remained hidden otherwise.From a practical view, our research challenges certain utopian assumptions regarding the stability and replicability of a one-size-fits-all model in organizational design. Instead, we recommend developing an in-depth understanding of an organization's specific context by means of sense-making activities. The latter should be performed in an ongoing approach to ensure that the organizational design evolves in keeping with its environment. 相似文献78.
Udell Monique A. R.; Giglio Robson F.; Wynne Clive D. L. 《Canadian Metallurgical Quarterly》2008,122(1):84
The authors examined the ability of domestic dogs to use human body cues (gestures) and equivalent-sized nonhuman cues to find hidden food in an object choice paradigm. In Experiment 1 the authors addressed the importance of the human element of the cue, and the effects of size, topography, and familiarity on dogs' success in using cues. Experiment 2 further explored the role of the human as cue-giver, and the impact of a change in the experimenter's attentional state during cue presentation. This included a systematic test of the role inanimate tokens play as cues apart from human placement. Our results indicate that dogs are more sensitive to human cues than equivalent nonhuman cues, and that the size of the cue is a critical element in determining dogs' success in following it. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
79.
Two experiments examined the viability of several explanations for why majority group individuals process persuasive messages from stigmatized sources more than those from nonstigmatized sources. in each study. majority group participants who either were high or low in prejudice or were high or low in ambivalence toward a stigmatized source's group were exposed to a persuasive communication attributed to a stigmatized (Black, Experiment 1; homosexual, Experiment 2) or nonstigmatized (White, Experiment 1; heterosexual, Experiment 2) source. In both studies, source stigmatization increased message scrutiny only among those who were low in prejudice toward the stigmatized group. This finding is most consistent with the view that people scrutinize messages from stigmatized sources in order to guard against possibly unfair reactions by themselves or others. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.
The rules and laws enforced in France in 1977 regarding the policy of old housing renewal have extended public intervention to the whole housing stock built before 1948. It came as a complement to the 1962 Malraux Law which exclusively concerned old city centres whose architectural value was preserved. Has the objective put forward to improve old housing by maintaining their residents (tenants and owner occupiers) been reached? The public policy of old housing renewal and its consequences on social occupancy are analysed in their relation to the ownership structure and to the property strategies of the actors who finance this rehabilitation. The paper examines Nord-Pas-de-Calais, one of the regions in France where the old housing stock is the lowest in quality. As for the social changes in the occupancy of these neighbourhoods, our 1995 study confirmed the results obtained in 1988. Four years after the end of the improvement programmes, these neighbourhoodshave retained a residential function for working-class occupants. However, two new trends emerged. On the one hand, despite a better integration of old housing in the policies implemented by local authorities since the 1982-83 decentralisation law, the incentive role of state aids to renewal is increasingly limited. On the other hand, property disinvestment has only been partially reduced. Some housing units remain unimproved and some buildings remain unoccupied. The housing supply is higher than the demand. Ownership of old housing is undermined by demand for housing estates in suburban areas. 相似文献